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Biomedical subjects

J A Murray

Publications and source records attributed to J A Murray.

At least 19 recordsLinked to original sources
PubMed1992

Water-flow sensitive pedal neurons in Tritonia: role in rheotaxis.

We have identified 13 pairs of neurons in the pedal ganglia of the marine nudibranch slug Tritonia diomedea that responded tonically and/or phasically to water-flow directed at the rhinophore sheaths and oral veil tips. Most of the neurons responded equally to inputs from either side of the body, but 6 pairs responded with greater intensity to ipsilateral water-flow stimuli. When stimulated intracellularly in a semi-intact, whole-animal preparation, 4 of these 6 pairs of neurons caused ipsilateral movements that may turn the animal towards that side. These observations suggest a role for these current-sensitive neurons in the previously described orientation to water-currents in Tritonia diomedea.

Action Potentials↗
PubMed1992

A comparison of facial grading systems.

There have been several attempts at establishing a grading system to estimate the severity of a facial palsy. This study compares the validity and consistency of all the leading systems. The results indicate that the systems are comparable and overall none had the advantage over the others. Interobserver variation had a significant effect on the consistency of the systems used, but experience of the observer was not a significant factor. The simplest classification studied was the House-Brackman system which is recommended.

Facial Paralysis↗
PubMed1992

Management of facial synkinesis with Clostridium botulinum toxin injection.

Associated movements after facial paralysis (synkinesis), due to unphysiological co-innervation of the facial muscles, often complicates the rehabilitation of patients following facial palsy. Clostridium botulinum toxin is a neurotoxin that interferes with the release of acetylcholine from motor nerve end plates, causing skeletal muscular paralysis. This paper concentrates on its clinical use in treating synkinesis affecting orbicularis oculi function and documents the results of treatment in 4 patients. Control of synkinesis, achieved in all 4 patients, was effective within a few days and lasted for 4-6 months. 2 patients developed transient diplopia and ptosis shortly after injection. However, no lasting complications or systemic side-effects were noted. All patients reported a significant improvement in their symptoms and reinjection at 7 months was carried out successfully.

Botulinum Toxins↗
PubMed1992

Guanylate cyclase inhibitors: effect on tone, relaxation, and cGMP content of lower esophageal sphincter.

Relaxation of the lower esophageal sphincter (LES) results from activation of its intrinsic innervation. This relaxation is associated temporally with an increase in the guanosine 3',5'-cyclic monophosphate (cGMP) content of the muscle. This study tests the hypothesis that variations in the production of cGMP mediate resting LES tone and nerve-induced relaxation. We examined the effects of guanylate cyclase inhibitors, such as cystamine and methylene blue (MB), on the resting tone, resting membrane potential, electrical field stimulation (EFS)-induced relaxation, and cGMP content of circular smooth muscle from the LES of the opossum. Strips of sphincter muscle were placed in a tissue bath and stretched to 125% resting length. Both cystamine and MB increased the resting tone of LES muscle in a concentration-dependent manner (EC50 = 1.1 +/- 0.2, n = 12, and 1.6 +/- 0.4 mM, n = 10, respectively). The increase in tone by cystamine was not blocked by tetrodotoxin, atropine, or propranolol. Cystamine (1 mM) did not alter the resting membrane potential of circular muscle cells of the LES. The removal of extracellular Ca2+ by the addition of ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA, 4 mM) and nifedipine (1 microM) shortened the duration but not the amplitude of the response to cystamine. Pretreatment with caffeine (5 mM) in the presence of EGTA and nifedipine to deplete intracellular Ca2+ stores blocked the increase in tone by cystamine. Cystamine (1 mM) failed to inhibit LES relaxation induced by EFS. Carbachol, at a concentration that induced a similar increase in base-line tone, attenuated the nerve-mediated relaxation. Cystamine did not alter basal cGMP levels, but inhibited the rise in cGMP induced by EFS. The data indicate that cystamine increases LES tone but does not inhibit EFS-induced relaxation, even though it inhibits EFS-induced increases in cGMP content. The increase in tone is dependent on the presence of intracellular Ca2+ stores.

Animals↗
PubMed1992

A single-blind, randomized study to compare the efficacy of two ear drop preparations ('Audax' and 'Cerumol') in the softening of ear wax.

A parallel group, single-blind, randomized study was carried out in a general practice to compare the effectiveness and tolerability of two ear drop preparations ('Audax' and 'Cerumol') in the softening of ear wax in 50 adult patients with impacted or hardened ear wax. Assessments were made on entry of the amount, colour and consistency of the ear wax, symptoms, and objective hearing. Patients were then allocated at random to receive one or other preparation and instructed to use the drops, morning and evening, for 4 days after which they were reassessed. Details were recorded of any side-effects or discomfort caused by the study medication and both physician and patients were asked to give their overall opinion of treatment efficacy. Both treatments were shown to be effective in the softening of ear wax and were well tolerated, there being no significant difference between the two groups in these parameters. However, patients who had abnormal hearing before treatment had a significantly greater improvement in objective hearing after treatment with 'Audax' ear drops compared to those patients treated with 'Cerumol' ear drops. There were no between-treatment differences in either either the physician's or patient's overall assessments of effectiveness.

Adolescent↗
PubMed1992

Benchmarking: a tool for excellence in palliative care.

Quietly and without fanfare, total quality management (TQM) is being implemented in a branch of health care where quality of care has particular impact on the patient's comfort and well-being. Some palliative care providers, dedicated to improving the quality of life for the dying, have fulfilled all the criteria to be contenders for prestigious quality honors like the Baldrige Award in the United States and the Canada Award for Excellence. Their secret is simple: the patient defines quality, and the palliative care team acts on that definition. Benchmarking, a TQM tool, allows institutions and organizations to benefit from sharing their best processes, and keeps the TQM continuous improvement cycle on track.

Home Care Services↗
PubMed1979

Arterial occlusion of pelvic bone tumors.

Arterial occlusion of the internal iliac artery was successful in the relief of pain due to primary and secondary neoplasms of the bony pelvis in 8 of 9 patients. These included 3 giant cell tumors, 1 aneurysmal bone cyst, 1 recurrent chondrosarcoma, 3 metastatic renal cell carcinoma and 1 metastatic clear cell sarcoma. Calcification of the margin of the lesion occurred in 3 of 4 primary neoplasms after infarction. The transcatheter arterial occlusion was accomplished utilizing Gelfoam and stainless steel coils. Although most patients experienced pain and fever for several days following the procedure, no permanent sequelae or complications were encountered.

Adenocarcinoma↗
PubMed1979

The value of percutaneous needle biopsy in the management of primary bone tumors.

Thirty-four suspected primary bone neoplasms were evaluated by needle biopsy at M. D. Anderson Hospital and Tumor Institute between September 1976 and February 1978. Adequate material for evaluation was obtained in 31 cases. The accuracy rate of the procedure was 93%. Needle biopsy is a rapid, effective and safe method of evaluating unsuspected primary lesions of bone. The indications, contraindications, and technique are emphasized. The benefits over open biopsy are indicated.

Adolescent↗
PubMed1979

Management and results of localized Ewing's sarcoma.

Seventy-six patients with localized Ewing's sarcoma who received primary treatment at M.D. Anderson Hospital from 1948 through December 1975 were reviewed. Patients have been divided into four groups according to the different treatment regimens they received: Group I, moderate dose radiotherapy alone; Group II, high dose radiotherapy alone; Group III, radiotherapy plus vincristine and cytoxan; and Group IV, radiotherapy plus vincristine, Adriamycin, cytoxan and actinomycin. The problem of local recurrence appears to be solved with combined chemotherapy and radiation therapy with only one of 36 patients having a recurrence at the primary site in Groups III and IV. Multimodal therapy is the preferred treatment to obtain control of the primary lesion by radiation therapy while preserving good function. However, the major cause of failure remains distant metastases, 19 of 36 (53%) in Groups III and IV. In addition, 4 of 10 patients who have survived over 5 years have developed osteogenic sarcoma.

Antineoplastic Agents↗
PubMed1979

Angiography in giant-cell bone tumors.

Angiography was performed on 48 patients with giant-cell bone tumors. Sixty-four per cent were hypervascular; 25% were hypo- or moderately vascular; and 10% were avascular. Findings were similar in the 45 benign and 3 malignant tumors. There was no correlation between the findings and degree of histological aggressiveness. There was a high (60%) incidence of aneurysmal bone cyst component in the hypovascular group. Hyperemic synovium, occasionally simulating tumor, was seen in 80% of surgically proved lesions. Angiography was useful in assessing tumor extent, particularly when an extraosseous component was present.

Adolescent↗